Gear-hobbing machine.



F. 0. PRWELL.

GEAR HOBBING MACHINE.

APPLICATION FILED 311111110, 1911.

Patented Mar. 31, 1914.

6 SHEETS-SHEBT l.

P. o. PARWBLL.

GEAR HOBBING MACHINE.

APPLICATION FILED JUNE 10, 1911.

1,09 1,493. Patented Mar. 31, 1914 6 SHEETS-SHEET 2.

F) 6 DIA. P. N #5 .5595 ANaqrTHn.

DER

Vroom F10. FRWELL.`

GEAR HOBBNG MACHINE.

APPLICATION FILED 111111110, 1911,

1,09 1,493. Patented 111131131, 1914.

6 SHEETS-SHEET 3.

J5 f2 Y 11111111111111111111 E. 0. PARWELL. GEAR HOBBING MACHINE.

APPLICATION FILED JUNE 10l 1911. 1,09 1,493. Patented Mar. 31, 1914.

`6 SHEETS-SHEET 4.

Wajses. /7

F. 0. FARWELL.

GEAR HOBBING MACHINE.

APPLICATION FILED JUNI: 10, 1911 1,091,493 Patented 1112111.31, 1914.

6 SHEETS-SHBBT 5.

F. 0. FARWELL.

GEAR HOBBING MACHNE.

APPLICATION FILED JUNmo, 1911.

1,091,493. Patented 1111111.31, 1914.

6 SHEETS-SHEET 6.

, Y l 49N 1 i i e. i 15w 55 i, 1v I 40 g 4 59 --i as j. v 33 1 O 51) 576@ r 14n/2:, y 1J f'f/ i v 6 0 T91 35 7.21` l n Q5 67 45 44 f5 Wzwes. l, M jak/for FAY 0. FARVVELL, OF DUBUQUE, IOWA.

GEAR-HOBBING MACHINE.

Specification of Letters Patent.

Patented Mar. 31, 19111.

Application led .Tune 10, 1911. Serial No. 632,395.

To c/ZZ ,rho/1L it may conc-em:

Be it known that I, FAY 0. FAnwELL, a citizen of the United States, and resident of Dubuque, county of Dubuque, find State of Iowa, have invented certain new* and useful Improvements in Gear-Hobbing Machines; and I do herebj.7 declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the artfto which it. appertainsto make and use the saine.

This invention relates to gear hobbing machines for hobbi'ng spur or worm gears` and the primary object of the invention is to provide a machine of simplified construction ha ving improved means to rotate the cutter or hob and the work in unison. without lost motion or springing of the parts such as would result in inaccurate and inferior work. Heretofore much difficulty has been encountered in constructing a mechanism to rotate the cutter and the werk in unison, with the cutter sufficiently free from lost motion. in the gearing associated therewith. the total of which lost. motion is usuallir suicient to contribute considerable looseness to the drive. Another ditlicult-v has been .to make the cutter spindle drive sufficiently compact and rigid to prevent lateral vibration of the cutter. In the ordinariY machines of this kind the mechanism for driving` the hob or cnttespindle has been constituted hv gearing` housed in the saddle supporting the spindle7 which gearing is connected with the main driving shaft through shafts and gearing betiveen the spindle supports and the housing. and eX- tending back into the main housing` of the machine. This construction necessitates the extension of the spindle supports out away from ,the main housing` (to permit of the shafts and gears mentioned) to a much greater extent than is conducive to rigidityT and compactness. This also necessitates the use of a large number of `ioints. shafts and gears to connect the hoh spindle with the main driving` shaft. with a correspondingly larfz'e amount of lost motion in the spindle drive.

In the present machine. the spindle drive,

instead ot' passino' through the saddleand housing. is located exteriorlv of the same.

so that 'Iain enabled to place the spindle bearinrjs'nnich closer to the main housing and to communicate motimi to the work table and hob spindle by a very few gears, shafts and joints. I

Other objects of the invention are to provide inuproved mechanism for varying the feed speeds; to furnish an improved arrangement and means for setting up the machine: and to improve machines of. this general tvp@ in numerous minor features, as will hereinafter appear.

In the accompanvine; drawings, I have shown a preferred embodiment of the invention. but it is to be understood that the machine mav be modified in numerous particulars within the liinits of the claims without departing from the scope of the invention.

In the drawings. elevation. partly in s i Fig. 2 is a top plan'view of the same. Fig. E is: a horizontal section through the hob Figure l is a 4partial side I saindle saddle and the ad'unctivc )arts on an irregular section line. F ft is a frontclevation. partlv in section. of the hob spindle and its saddle. Fig. 5 is a side elevation. parti)v in section. of the parts shown in Fig. i. Fig. (l is a horizontal section through the gear box'. Fig. T is a fragmentary ide elevation. pai-tlv in section. of the `gear box and the a "arent mechanism. Fig. S is vertical transverse section through the gear box and its associated mechanism. Figs. Si. 10 and l1 are detail views of thc mechanism for feeding the work table toward the cutter in cutting' worm gears, Fig. 12 is aidiagrammatic view shofing the method of and means for setting the hob at the proper angle. in cutting spur gears, and Fig. 18 shows on a larger scale the gage illustrated in Fig. l2.-

Referring to the drawings. and particularl)Y to Figs. l and Q. the housing A. of the machine is shown as provided with an upright standard or housing AX, which is provided with a finished vertical surface A2 overhanginga tinished horizontal surface A3. On the horizontal portion .L3 of the main housing a work holding saddle B is mounted to move toward and awav from the vertical surface A2. and on the-latter surface is a vertically slidable saddle C. On this saddle is a sub-saddle D on which a plate E carrving the hob spindle F is mounted to turn in a vertical plane. The hob spindle l is driven b v means of a bevel gear f on one end of the same meshing with a bevel non. of the machine.

pinion f on a stub shaft f2 extending along- I dicated at f3.' The stub shaft f2.is driven by -means' of a universally jointed telescoping shaft f4, operated from a main drive shaft Gr, rotated by a stub shaft .H having` a bank of pulleys It. and equipped with a lbevel pinion h meshing lwith a seco-nd bevel pinion 71.2 on the 'shaft G. The shaft G therefore serves tofdrive the hob spindle, and ,it further serves to rotate the work table o associated with the work saddle B. The work table b carries a worm wheel b in mesh with a worm b2-on a drive shaft 'I which is driven from the main driving shaft G through the gears g',.g, g2, g3, g4.l The number and arrangement A of these lastnamed gears, may,'however, be varied, as

desired. Thus it will be evident that. the shaft G can be considered the starting point for the application of motion to both the acting element of the machine and the element acted upon, and'that the number of transmitting devices between said shaft and said elements is reduced to av minimum, with a consequent 'decrease in the lost motion.

' Of-'course yany looseness inthe bevel gears 12,', 11.2 willnot affect the results, as will be understood. It will also be noted that the hob supports are at a minimum distance from the -main housing A of the machine,I wherefore the 'construction is rendered rigid and compact. The sub-saddle D of the cutsaddle -D isV provided with a substantially,

' circular groove 16 on its front face, which groove is of approximately T-shape section. The hob-carrying plate E is provided at4 its rear face with lugs -17 which extend into the groove 16 as indicated in Figs 3 and 4,

whereby said plate is mountedufor turning movement on the 'sub-saddle in a vertical plane. Such afmo'vement' oftheplate will tiltthe hob to the required angle with respect to the vertical when it is desired vto cut spur gears, and the-.plate is heldtoth'e subsaddle and secured thereon in the desired adjustment by-fineans of bolts 18 vhaving T shaped heads 19 (Fig/5) fitting 1in thewidened portion .of the groove 16 v'and equipped at'their forward ends with clamping nuts20.

Figs. 2,3' and. 4 show a .hob 21 mounted on the hob spindle F between-a "fixed bracketV 22 onthe-plate E, anda removable bracket 23 at the opposite lside vof said plate. The bracket 23 is providedat its lower part'with a vdove-tail ledgeextending around' the correspondingly shaped lower edge of the of being out.

spindle plate, (Figs. 4 and 5) and at'its l upper part said bracket is traversed by4 nutted bolts 25 having T-hea-ds 26 vengaging a .groove 27 in the plate arranged parallel to the spindle. By this arrangement the bracket 24 is held to the spindle plate by screwing up the nuts on the bolts 25, and if it is desired to remove the hob, it is simply necessary to loosen said nuts and slide the bracket off the plate, the end of groove 27 being left open for'this purpose. The spur gear blanks to be operated upon by the hob.

21 are centered on the work' table b by means of an upright arbor b", as indicated in Flgs. 1 and' 2. In Fig. v2 the top blank is shown at by, and it illustrated as in the process The blanks are preferably supported on the table from beneath by means ofone or more-blocks or rings b", `as shown 1n Fig. 1j. When the work 1s heavy 1t is desirable to support theworkarbor of at lthe top'by-m'eans such asa support 28. This is preferably constituted by a V-shaped de- -vice swiv'eled lon an upright rod 29' at one side of the machine and adapted to be swung with its lintermediate portion against the upper-end of the work arbor, in which position the free. end of said device :may be tially embraces, by a set screw 31. The upright .rods 29, 30 thereby firmly hold the arbor support against displacement away vclamped ,to an uprightrod 30, which itparfrom the cutter, and the work is made very Y accurate. When' the*` blanks are finished they can be-rernoved easily from the arbor after the support 28. is swung away from the arbor on its pivot rod 29, the set screw 31.-

being first loosened. The hobsaddle C .is moved up and down on the` surface A2 by means of an ordinary threaded spindle 32 `housed in the part AC' -On top of spindle 32 is arspur gear 33 meshing' with a spurgear` 34 at'th top of a shaft 35 also housed in Athe part- A. This shaft 35 is rotated from of which they are made, andthe change speed mechanism insures-a 'proper feeding` movement of the hob saddle vunder any given conditions. In the embodiment'illus'trated,

thefchange speed mechanism is constructed lsubstantially as follows: The Wohle' table shaftfI extends through the bottomofthe gear box or casing K, as best shown in Figs.

7 and 8. .Within said vc'asingthis-shaft has vkeyed to it=a bank of gears denoted generally by reference character L. Journaled in the casing o r box above the shaft I isa v'short shaft M. On the shaft M is 'a bank of gears N adapted to coperate with the bank L 1n transmitting movement from shaft I to shaft al, at any of a number of speeds. In the embodiment shown, each bank of gears consists of five wheels, so that five speeds may be provided. 'l` he gears of the bank N are le-cse on the shaft El. but any one of them is adapted to beloeke'd to said shaft in order to be thereby brought into operative connection with the Corresponding gear on shaft L, b -v means suoli as are common in lathes and similar machines. This means may be of any appropriate character, but in the inachine illustrated, the central openings of the gears N are grooved, as indicated at n, and adapted to be engaged by a spring pressed finger #housed in a eut-out shaft 'n2 adapted to be moved into and out of an open space in shaft M, which has a slot n3 through place that geai` in operation.

which the end of the finger a projects to lock the gear alined therewith. The outer end of shaft 'n2 is formed as a circula-r rack n4 with which coacts a pinion a5 operated by a knob nfl. By turning this knob the shaft n* may be moved in and out with respect toshaft Mso that the finger n can be engaged with the desired gear of bank N, to From shaft M motion)is transmitted to a third shaft O in the gear box'. Shaft lsf has keyed thereon, but slidable lengthwise thereof, two gears 0, o arranged side by side and preferably integral with each other. These gears, of which o is the smaller, are shiftable lengthwise on their shaft by means of a fork 02 operated by a knob o3 at the exterior cf the gear box. `lVlien the parts are in the position shown in F ig. 6, the small gear o is in mesh with a large gear p on shaft O, but when the .large gear o is shifted b v the. knob o3 to the right with respect to Fig. G, it can be engaged with a small gear p on shaft O, whereby the speed imparted to the last named shaft can be materially increased. Thus it will beseen that five additianal speeds are providedfone for each position of the gear banks L, N. The arrangement is' preferably fsueh that the fastest speed when gears o, ,n are intermeshed is not quite as fast as the slowest speed when the gears o, 7.2 are in mesh with each other. The shaft C), which can, as indicated, be driven at any of ten speeds, has keyed thereon a worm 36 which meshes with a worm gear 37 loosely rotatable on the shaft hereinbefore described. By coupling the worm gear 37 to the shaft 35 the latter may be. operated at any ofitex; speeds, and this may be accomplished b v means of a collar 38 on said shaft, which follar slidable on the shaft along a key which prevents its rotation on the shaft. The collar Il?. and worm gea-r 3'? are formed with coaeting toothed faces 3S, Sforming parts of a clutch. The collar or clutch membe'L 238 can he raised and lowered b vmeans of a bell crank lever 39 pivoted at 40 and provided yith a terminal lug 4l adapted to plies oilto the heb through a tube 66, said 13G take into a cut-away portion or recess 42 in an upright rod 43 movable vertically in the gear box K. When the parts are in the position shown in Fig. 8, the abutment of the lug 4l of lever 39 against the solid portion of rod 43 above the recess 42 will hold the clutch member 3S in its raised or disengaged position, so that the rotation of shaft O will not affect the saddle driving shaft-35,'but if the rod 43 is raised from the position shown the lug 41 will take into the recess 42 and therebypermit clutch member 38 to drop by gravity into engagement with the clutch face on the worm gear 3T. The shaft 35 will then be rotated at a speed corresponding tothat of the shaft O. The clutch operatingl rod 423 may be operated by hand by means of a -small lever 432L at the front of the machine,

which lever is mounted on a rod 44 extending lengthwise of the machine and equipped with a small lever 45 pivoted at 4G to the lower end of the rod 43, as shown in Fig. 8. The saddle C carries a bracket 47 which loosely surrounds the rod 43 and is adapted to coact with upper and lower nuts 48, 49 threaded on said rod above and below said bracket. In this manner, the saddle C may operate the rod 43 automatically in order to start and discontinue the downward feed of the saddle at the desired points, as will hereinafter appear. In order to permit the saddle C to be raisedand lowered by hand, and to be raisedrapidly by powerv after the eut has been completed, the shaft is continued downward beyond worin gear 37, and it is provided at its lower end with a bevel gear 50 meshing with a bevel gear 5l on a shaft 52 extending throughout the length of the machine. within the housing. At the' front of the machine this shaft is provided'vith an operating lever 53. Atthe rear of the machine, the shaft 52 has keyed therm In a clutch member with which coacts a wide gear 55 loose on the shaft 52 and having a clutch face to coact with that of the member 54. The gear 55 is solid with a spi-ophef. 56 driven by anendless chain .3T running over a sprocket 5S on the main drivin;y` shaft G, and the gear .7.1 and sprocket im are movable along the shaft .72 imo :ip/position in which the two clutch faces are ei'.- gaged, whereupon the shaft 52 willy be rotated by the chain and sprocket transmission described. The sliding movement. of gear 55 to produce this result is effected hv meansof a fork 59 on a rod 60 mounted in brackets Gl, 62 on 'the machine housing and havingY its forward. end engaged with a cam G3 -secured to the rear end of the rod for operating the clutch of the vertical saddle. The gear 55 is Continuously rotated from the main driving shaft, and in all of its positions it is engaged with a gear G4- on the shaft ef a smalll lubricating pump 65,-'which supliti pump being therefore 'continuously operated.' It will now be understood thatwhen, in 'feeding downward, the vertical saddle C reaches what should 'be its downward limit of movement, the bracket 47 on said saddle will engage and depress the lower nut 49 on the rod 43, which nut has previously. beenA setin the desired position. The rod 43 will thereby be'depressed and the clutch member i0 38 disengaged from the worin wheel 37, so )that the`- downward feed of the saddle will be arrested by the discontinuance of the rotation of shaft 35. At the same time, the depression of rod 43will cause the turning `iof rod 44 by means of the lever 45, and this will result in such an actuation of the cam 63 as to pull forward the rod G0 and thereby engage t 54'. As the gear 55 is rotated vcontinumisly throughout the operation of the 1nachine,as above described, it will thus, .when engaged With .clutch member 54, rot-atethe shaft in such4 a direction that by means of the intermeshing bevel gears 50, 51, vthe shaft. 35'

will be rotated in a direction opposite to the initial direction. The vertical return movement of thesaddle. C will thus be vproduced automatically by power, and it will be noted that the arrangement is such as to produce this powerreturn at a comparatively high speed, .considerably exceeding that of the downward feed. lVhen, in rising, 'the bracket 47 on the saddle abuts the upper nut 48 on" the rod 43, which nut has first been setV the desired position, the rod 43 is raised-again, thereby disengaging the clutch 54, 55.'. The clutch 37, 3S is renga-ged by handafter anew set of blanks is placed in the machine.

The two clutches above mentioned, formingpartof" the1 mechanism for raising rand lowering the 'saddle may beV operated by hand if desired' by 'means of the lever 43 on therod 44, which is suitably turned to eiiect the desired movements of Vthe 4lever 45 and f' cam 63.. The saddle may be raised and lowered by hand by means of the lever 58 on /4' the shaft 52.

-From the foregoing, the operation of'cut tin spur gears will -no doubt be readily un erstood The manner of mounting the l'gear blanks .and of rotating the sa'me and the cutterv in uni-son 'has already been described. The gear g4 of the train connect- .ing the main driving shaft Gr With the work table'shaft I must have anu'mberof teeth' corresponding: with the number of teeth to befcutin the blank, andi ,said gear is readily :removable for the substitution' of other 30 gears, as the size of the blanks is changed. As previously intimated, the train of .gears just mentioned may consist of different numbers of gears, as required by convenience and the conditionsof actual practice. The f 65.specificmanner of mounting these gears is ie gear with the clutch member head.

of the pla-te E in the manner previously de scribed.- ln order to --set the hob with great accuracy, a gage R is employed, as indicatedin Figs. 12v and 13. This gage consists of a metal piece or block having a sloping or in clined edge lr, the inclination of which corresponds with the angle of the hob thread in' any given case. Tliatisto say, a number of such gages are employed 4corresponding to the` different anglesnf' the differenth ob threads. The inclined edge r of the gage-'is placed against a flattened surface c at the top of the plate E, as shown in Fig. 12, and the plate is then turned about its axis until the straight 'side r ofthe registers with -a straight 'mark or incision 'r2 on the sub'- saddle `D. The plate is 'then clamped tightly to the sub-saddle in the required adjustment, as previously dv 'ribed, and the hob will'be. found to be p tioned with great accuracy; This arrangement presents a distinct advantage orer that adopted inthe 'ordinary gear bobbing machines, in which the setting of the angle ofthe hob is'elfected by means of a protractor or graduations on the swivel As the angle often expressed-in seconds aswell as 4degrees and minutes, the protractor is unreliable asy seco-nds cannot be read on a protractor of small diameter. The improved system herein described entirely eliminates, however, this disa'dtantage and makes the'accurate setting` of the hob a vcomparatively easy matter.A The gages R may also-be used to serve an additional func` tion, as will hereinafter appear. Preferably each gage is provided with ahole R inthe body thereoftso that the samefmay beconveniently carriedon a ring, suspended Ona hook or for analogous purposes.

Then cutting wormjgears, the hob'has its axis located perpendicular 'to the plane of the vertical axis ofA the Work. It is' not moved vertically during, the cutting operation, as with spur gears, but itis set' centrally with respect to the Worm Wheel blank and the table is fed toward the hob until the blank is cutto the" proper depth. The sad-4 dle B which supports the .Work table b is moved along'the horizontal'surfaee or slide A? of the machine by means of a screw 67 engaging a threaded lug or` nut 68 on the lower part of the saddle withinthe housing.

A crank 69 on theforward end ofthe screw spindle 67 .enables the saddle to be moved toward and away from the cutter by hand.

The screw spindle 67 is extended well back into the housing of the machine, Where it issuitably supported, and adjacent its inner ratchet teeth, as best shown in Fig. 10. The

ratchet is provided at one side with a clutch face formed of a series of angular projections adapted to enga-ge similar projections on a clutehfacc 76 with which a .sliding clutch member 77 on the shaft 67 is provided. The clutch member 77 is keyed against rotation on the shaft 67, but is slidable along its key, so that the clutch faces 75 and 76 may be engaged to rotate shaft 67 from the shaft O. The clutch member 77` is provided with a plurality of interior spring-pressed balls or pieces 78 (Fig. ll) adapted to rest in either of two grooves 79, 80 cut transversely in the shaft 67, so that when said clutch member set with its balls 'or` nieces '78 in one of said grooves, such member may not be displaced from that position Without the expenditure of a fair amount of force; The clutch member 77 may be clutched into engagement with the ratchet 70 by means of a forked member Si embracing said clutch member and pifoted to the machine frame at S2. This firked 'member 8l is provided with a rod S2 extending to the forward end of the machine, where it is-equipped with an operating` knob S4. TWith the described arrangement, the clutch members aforesaid may be engaged by pushing on the knob 84. Then if the machine is in operation with the shaft rotatingat the desired speed, a proper movement of rotation will be transmitted to the work saddle spindle 67, which will thereby be fed against the cutter or hob, at the proper speed, while the `work table b`rotates. In order to stop the work saddle at the pro-per point I employ a stop screw which may be conveniently positioned o-n the housing beneath the gear box and which has a hai dened end to coact with a hardened plug 66, secured to the inner portion of the work saddle base. The stop screw S5 may be fixed in the desired position by means of a lever opera ed set screwl S7, as shown in Fig. l. Yhen the hardened plug 86 on the saddle abuts the end of the stop` sciew the resistance to the rotation of the saddle spindle. 67 will be such as to cause the clutch inembers 75 and 76 to disengage themselves automatically. This is produced primarily by the angle of the operating teeth of the clutch members which, under the conditions described, will cause the clutch member 77 to be thi-,ust away from clutch member 70 in Vspite of the engi'igemeiit of the balls or pieces 78 in the groove of shaft 67. The clutch member '77 will therefore be pushed.g to the left with respect to Fig. 9 until it takes the position shown in that ligure, wherein the spring pressed balls or pieces 7S are engaged with the groove 79. It will therefore be understood that when the clutch members 70, 77 are engaged by operation ofv the knob 8st, the clutch members will be held together with sufficient firmness and rigidity, by' theY frietional means described, to produce the rotation of spindle 67 and the feeding of the work table in a reliable fashion until said table'engages the stop screw S5, whereupon the feed is immediately discontinued in a reliable and automat-ic manner.

The gage R previously described may be used to great advantage to facilitate the setting of the stop screw S5. A separate gage is provided for each gear pitch. The gage shown is, say, for use with six pitch gears.

a six pitch tooth, which is .3595. In using the gage an accurately sized gear blank is placed upon the arbor and the table is advanced until the hoh just touches the blank. The stop screw S5 is then tightened up against the end r* of the gage, which is interposed between said screw and the liardeiied plug 86 on the work saddle. The

gage is then withdrawn, the hob raised and the table advanced as far as thel stop screw will permit, in the manner previously indicated. This will insure the cutting of the teeth exactly .3595 deep, without liability of error. The use of the gage for the two purposes indicated, is therefore of considerable importance in a convenient and accurate operation of the machine. 1t will be understood. that the gage may also be used in setting up the work saddle in cutting spur gears. ln this case, as is well understood, the work saddle is lso fixed in position that the hob, in being fed downward across the several blanks which may be cut simultaneously under these conditions, begins and/continues to cut to the full depth required.

What I claim is l. In a gear liobbing machine, a vertically slidable Vhob saddle, a hob spindle carried thereby. a main driving shaft, means to transmit mbtion from said shaft to said saddle, a rod provided with shoulders adapted to he engaged by said saddle in its movement to raisey or lower the rod, said rod provided with a iiecess, a trigger adapted to be actuated by said recess, and'a clutch adapted to be operated by said trigger to cont-rol the movement of said saddle.

2. In a gear bobbing machineca hob saddle mounted for vertical movengent, a hob spindlecarried by said saddle, a horizontal The end portion fr is therefore in this case equal in thickness to the depth of work table, a main'driving shaft, means to impart motionifrom 'said shaftto the sad actuatedmby said recess', said lever adapted' to operatesaid clutch 'mechanism' to control "the movement of said hob saddle, meansto rotate the Work table, and means Gepes fof 'this patent may' be obtained for dle, and means comprising a universal stub.

shaft -to impart motion to the spindle, means. to impart a rotary motion to said table, means to .trip the'vertical movement of saidA hob saddle comprising a rod actuated by said saddle, said rod provided with a'. recess,

a trigger' adapted` to bel actuated by saidl recess, and a clutch mechanism adaptedto rbe operated by saidltrigger.

3. In a gear bobbing machine, a verti.n

cally movable hob saddle, a hob spindle carried thereon, a rotatablev work table, a.

main driving shaft, means to impart motion from said shaft to the hobsaddle com? prisinga change speed mechanism, a ver-- tical shaft, a worin driven 'by the change speed mechanism to operate said vertical shaft, a clutch mechanism disposed 4on. said 4vertical shaft, a rod actuated bythe hob saddle Ain its movement, said rod provided with a recess, a trip lever adaptedto be comprising a universal stub 'shaft driven by the main shaft to rotate said hob spindle.

.l 4t; In a gear-bobbing mechanism, a ver-` tically movable hob saddle, a spindle on said saddle,'a"rotatable and sliding Work table, means to operate said saddle and said spindle, means to rotate said table, and means to feed said table toward said hob Saddleaidmeans comprising a screw shaft, a clutch" keyed to said shaft, a ratchet loosely ymounted, on said shaft, an eccentric bushing adaptedto continually rotate said ratchet, and means to'oper'ate said clutch to cause 'the ratchet wheelv to operate the.` screw "shaftA thereby feeding' the Work table.. as

aforesaid.

' 5. In a gear hobbingfmachine, tliecomaV bination o a supporting.. member, plate swiveled .thereon and carrying `a hob spindle, said lplate havinga flattenededge, and-a gage piece having* a tapering lside to abut' said flattened edge and. adapted to register` with a suitable 'mark' on v the supporting member.

6. In a gear bobbing machine, the coin-, bination of a supportin-g member, a plate swiveled'thereon and (':arryin-gav hob spindle, said plate having' a iattened edge', a work saddle, 4means to .move said work lsaddley toward'said cutting mechanisin,.ga hardened plug on the saddle, a longitudinally adjustablestop screw to abut saidhardenfed plug 8. In avgearl bobbing .bination-of a swiveled plate carrying a hob saddle, a work saddle movable toward and away from said spindle, and a gage having one portion which cooperates with said plate .to indicate the adjustment of the saine, and

another portion which indicates the proper adjustment 'of the movement of the work bination of-,a swiveled plate carryinga hob saddle, a work saddle movable toward and away from saidfspindle, and al gage having a tooth depthdeterniining portion'4 and. a

.plate positioning po1tion,?said iirst named portion having acut out part which' determines the amountl of4 movement of said work saddle 'and said last named portionhavingla `tapering, side'to' determineV the angular position of said plate,

9. In a gear bobbing machine, avert'ically movable hob saddle',- an actuating shaft.

therefena gear loosely "mounted -on said shaft, clutch mechanism to operatively con- -nect said gear and shaft, a.r0d actuated by said hob saddle in its movement, said rod provided with-a-.rece'ss, and' a trip lever Vactuated by said l' recess, said trip lever adapted to operate said-clutch mechanism.

10. yInv a gear bobbing machine, the com bin'ation of -cntting mechanism, ay work saddle, manually operable means to. move said saddle toward and awayffrom the cutting ',mech aiiisin,v Vpower operated 4means *adapted to'4 actuate saidmanual-ly operable means comprising. a clutch interposed between -said power operated means and said- 1'I n'ani'iall'y operable mea-ns, saidclutc'h com@ '-,prisingopposing toothed' surfaces' and' hav .ing means-to hold it rictionallyin .its engaged position, means interposed in the path -of movemeut'of said saddle to increase [the 4'resistance oli-ered thereby to the operating mechanism, said clutch adapted to be ,auto-` matically disengaged when the' resistance offered by said saddle-issuincreased.

Intestimony whereof Il aiX my signature. in presence of two witnesses. Y FAY O.- FARWELL, 'VVitnessesz i R. W. BossH'ART. GLENN MUFFLY.

ive cents'each, by addressing the. Commissioner of Patents,

Washington,).. 

